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arXiv:1705.10679 · Physical Review Letters

State-Independent Uncertainty Relations and Entanglement Detection in Noisy Systems

René Schwonnek, Lars Dammeier, Reinhard F. Werner

Published Oct 27, 2017• 62 citations
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Abstract

Quantifying quantum mechanical uncertainty is vital for the increasing number of experiments that reach the uncertainty limited regime. We present a method for computing tight variance uncertainty relations, i.e., the optimal state-independent lower bound for the sum of the variances for any set of two or more measurements. The bounds come with a guaranteed error estimate, so results of preassigned accuracy can be obtained straightforwardly. Our method also works for postive-operator-valued measurements. Therefore, it can be used for detecting entanglement in noisy environments, even in cases where conventional spin squeezing criteria fail because of detector noise.

DOI
10.1103/physrevlett.119.170404

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